Abstract: A coupling device for coupling two or more ducts together includes a number of frames each having four beams secured together for forming a square shape and for securing onto the ducts. The beams each includes a flange extended upward and each includes a panel formed on each of two ends and inclined relative to the beams. A number of fasteners may secure the panels together for allowing the beams to be secured to the duct. A number of blocks may be engaged between the panels for allowing the beams to be secured to the duct of greater size.